Quenching apparatus



Qc t. 4, 1960 H. E. MESCHER ET AL 2,954,789

QUENCHING APPARATUS 2 Sheets-Sheet 1 Filed Feb. 18, 1959 INVENTORS f/AFOZD M55095? BY A ' Attorney O t, 4, 1960 v H. E. MESCHER ET AL 2,954,789

QUENCHING APPARATUS Filed Feb. 18, 1959 2 Sheets-Sheet 2 apparatus; and

Unite States atent O QUENCHJN G APPARATUS Harold E. Mescher, Rivera, and Walter E. Heyer, Whittier, Cahfl, assignors to Pacific Scientific Company, San Francisco, Calif., a corporation of California Filed Feb. 18, 1959, Ser. No. 794,029

13 Claims. (Cl. 13457) This invention relates, generally, to quenching apparatus used in the heat treating of metals and alloys, and the invention has reference more particularly to a novel quenching apparatus especially suitable for handling large, hollow members open at one end and closed at the other end, such as missile bodies, airplane parts, etc.

In the quenching of heat treated large metal, hollow bodies, it is important that the body be chilled on the inside as well as on the outside, and, as the chilling liquid moves up the outside of the body, it should simultaneously move up the inside of the body and at the same rate, otherwise distortion and warpage as well as a non-uniform quenching will result, so that the resultant product is not only distorted in shape but will have unequal stresses therein resulting ultimately in premature failure.

Quenching apparatus as heretofore constructed do not provide for the chilling of the inside of large vessels or bodies in synchronism with the chilling of the outside of the same, resulting in defective parts.

The principal object of the present invention is, therefore, to provide a novel quenchin apparatus adapted to quench uniformly both the inside and outside of a hollow body simultaneously, resulting in a uniform product with uniform stresses substantially throughout the body and without any distortion taking place within the body as a result of the quenching process.

A feature of the present invention is to provide a novel quenching apparatus of the character described that is capable of handling quite large bodies or parts readily and quickly by the mere insertion of the body or part into the novel liquid filled apparatus of this invention, means being provided for evacuating the air from within the body or part during the quenching operation and for circulating cooling fluid both along the inside and outside of the body or part during such operation.

Still another feature of the present invention is to provide a novel quenching apparatus of the above character that is adapted to quench large bodies without the necespanying drawings wherein:

' Fig. 1 is a vertical, sectional view of the novel quenching apparatus of the present invention illustrating a hollow body being inserted thereinto to eifect the quenching of the body;

Fig. 2 is a view, similar to Fig. 1, but illustrates the position of the body being quenched substantially at the time the body has been fully inserted into the quench Fig. 3 is an enlarged, partial vertical, sectional view of a portion of the structure shown in Fig. 2.

"a "quench tank 1 open at its topand closed at its bottom, and of substantially cylindrical shape.

This tank may be quite large so as to be capable of handling hollow parts Ice Patented Oct-4,19QQ

of the order of six feet in diameter and as large as twenty feet long, or longer, such a hollow part or body 2 being, illustrated in the drawings as being quenched in liquid 3 in the tank 1. If desired, the tank 1 and the associated apparatus shown can be sunk into a big hole in the floor, with the top portion of the tank substantially at floor level; This arrangement is particularly desirable where the part to be heat treated is large and is heated in a furnace positioned above the quench tank 1. In such a case, the hollow part 2 is initially pulled up into the open bottom of the furnace for heating as by use of suitable load handling apparatus such as that disclosed and claimed in co-pending patent application Serial No. 794,050 for Load Handling Apparatus, in which application Harold E. Mescher, one of the present applicants, is a joint inventor, both of which applications are owned by a common assignee. l The upper portion of tank 1 is surrounded by an annular quenching liquid storage jacket 4, which jacket is adapted to receive liquid 3 spilling over the upper edge 5 of tank 1, this tank being open at its top. Normally, the level of the liquid in jacket 4 is lower than that in the main body of the tank 1, as is illustrated in Fig. l. Spacer webs 6 having bevelled upper edges for guiding the load handling apparatus and treated bodies into the tank 1 are spaced around the upper edge of the tank and extend across the hollow interior of jacket 4. These spacer webs carry a transverse load ring 7 upon which the load handling apparatus and its load is adapted to rest when the work piece 2 is fully inserted into the tank 1.

At the center of the tank 1 there is provided a vertically extending tube or pipe 8 that is fixedly supported at its lower end upon an annular ring member 9 that in turn is carried by a surrounding sleeve or tube 10 depending from the bottom of tank 1. The tube 8 extends upwardly within the tank 1 and has a telescoping extension tube or sleeve 11 mounted on its upper portion, the said tube 11 being supported upon stationary tube 8 and being movable vertically with respect to this 'latter tube, as will further appear. Positioned upon the upper open endof the tube 11 is a cruciform vent cap 36 which may be removable from the top of tube 11 and is formed by plates'or webs arranged at right angles to each other, the upper edge of these plates being curvedsubstantially in conformity with the curvature of the closed end of the part 2 to be quenched. This is done in order that the pressure of the part 2 upon the telescoping tube 11, when this tube is pressed downwardly in use, as will further appear, acting through the intermediary of the vent cap .36, will not cause the upper edges of this cruciform vent capto exert excessive distorting pressures upon the hot part 2. Differing vent caps having differing upper edge contours to suit the different parts treated may be used interchangeably. With the. part 2 resting on vent cap 36, the cruciform structure of this cap permits liquid or air to pass from the interior of part 2 into tube 11 (see Fig. 2). The telescoping tube 11 has a ring member 12 (see especially Fig. 3) secured to its lower end, which ring member closely surrounds the stationary tube 8,.the said ring member being provided'with depending legs 13, shown as three in number, which carry the weight of the telescoping tube 11 and have their lower ends attached to chains or cables 14 that pass over sprockets or sheaves 15 carried by brackets 16 fixed upon the stationary .vertical tube 8. The chains or cables 14, after passing over the sprockets or sheaves 15, extend downwardly and have their lower ends attached to an annular counter-weight 17 that surrounds the tube 8. The lower portion of the telescoping tube 11 has a hollow, cylindrical skirt 18 bevelled at its upper end attached thereto and surrounding the ring member 12 and the weight 17 and its supporting sprocket chains and sprockets, so that the load handling apparatus and any work thereon such as the ject above the liquid as illustrated in Fig. 1.

part 2 being passed over the tube 11 will not strike I against these members. what heavier than the telescoping tube 11 together with that of its skirt 18, so that the tube 11 is normally held in its. uppermost position shown in Fig. 1, so that the top thereof projects above the level of liquid 3 in tank. Thus, normally, the liquid 3 reaches to the brim or upper edge 5 of tank 1 and the upper end of tube 11 will pro- The relative weight of the counter-weight 17 will determine how much pressure must be applied by the part 2 or other work piece upon vent cap 36 to depress the telescoping tube 11 and force thesame downwardly and into the liquid 3, as will further appear. This pressure cannot be excessive for otherwise the relatively hot part 2 might be distorted.

The lower end of tube 8 extends into the upper por-- tion of a sump tank 19; this tank is adapted to contain the liquid 3 for the greater part or all of its height, determined by the operation of the quenching mechanism and by the setting of a liquid level switch 20 controlling the motor of a scavenger pump 28, which pump can pump quenching liquid from tank 19 and communicates through pipes 29 and 30 as shown by the arrows into an annular quench manifold 31 in quench tank 1 having a series of exit openings 32 in its upper surface through which such liquid passes into tank 1. The liquid level switch 20 is so set that normally it is open unless the liquid within sump tank 19 rises above the bottom of a transverse passage 21 extending from the upper portion of this tank. When the top of tube 8 is above the surface of cooling liquid in tank 1, the liquid level in sump tank 19 is normally below the lower open end of tube 8, as shown in Fig.1, so thattube 8 and the transverse passage 21 extending out of the upper portion of tank 19 are in communication, whereby air passing down through tube 8 in use can pass out through the passage 21, through a liquid filter 22, and out through a transverse passage 23, into a vertically extending standpipe 24. Standpipe 24 is open at its top which extends above the liquid level in tank 1, so that air can escape into the atmosphere.

A liquid level switch 25 communicates with the standpipe 24 and, when the level of quenching liquid in'standpipe 24 reaches a predetermined height, as will further appear, determined by the setting of the liquid .level switch 25, this switch serves to energize motors driving circulating pumps 26- and 27. Pump 26 is adapted to draw quenching liquid from filter 22 and drive the same up through a passage 33 as shown by the arrow and into aplenum chamber 34 surrounding tube situated below the tank 1 and communicating therewith through a series of openings 35 arranged in a circle about the supporting tube 10. Pump 27 is adapted to draw quenching liquid from the storage jacket 4 through a pipe 38 and to drive this liquid through pipe 30, as shown by the arrows, into the quench manifold 31 for forcing the same up into the tank 1, as will further appear.

In operation, the counter-weight 17, acting through cables or chains 14 and legs 13, normally serves to hold the telescoping sleeve 11 in its uppermost position, as shown in Fig. 1, in which position the upper end of this sleeve and the cruciform vent cap 36 on top thereof are positioned above the liquid level in tank 1. Also, the liquid level in storage jacket 4 is about as shown in Fig. 1, i.e., somewhat below the level of the liquid in tank 1, which liquid level is practically at the brim ofthe tank. The hot part 2 to be quenched is now lowered as by use of the Load Handling Apparatus disclosed in copending application heretofore noted, so that the bottom open end of the part 2 enters the tank land commences to move .down in this tank. In order that the quenching liquid,

The counter-weight 17 is somea and this escape is provided by thevent cap 36, telescoping sleeve 11 and tube 8. Thus, air within the member 2 will flow inwardly through the cruciform vent cap 36, as shown by the arrows in 'Fig. 1, downwardly through sleeve or tube 11, through tube 8, into the upper portion of sump tank 19 and outwardly through duct 21 which is empty of cooling liquid at this time, through filter 22, duct 23, andout through Standpipe 24. into the atmosphere. Thus, the quenching liquid moves up the inside and the outside of the part 2 at the sarneuniform rate, enabling uniform quenching of this part and preventing the same from becoming distorted due to uneven cooling which would otherwise, take place but for the presence of tubes 11 and 8. Some liquid will spill over from tank 1 into the storage jacket 4 during this operation.

Continued downward movement of the part 2 will I eventually cause the closed upper end of this part to strike the vent cap 36 and depress telescoping .tube 11 by overcoming the counter-weight 17. As the top of tube 11 is depressed below the liquid level in tank 1, liquid will start to flow through the cruciform vent cap 36, as shown in Fig. 2, and into telescoping tube 11 and tube 8, thereby filling these tubes with quenching liquid, as shown in Fig. 2, together with the sump tank 19, passages 21 and 23, as well as the filter 22. The liquid level will rise in stand pipe 24 to seek its level with that of the liquid in tank 1. When the height of the liquid in standpipe 24 reaches that set by the liquid level switch 25, this switch will close and energize motors driving pumps 26 and 27. Pump 26 will draw quenching liquid from the filter 22 and drive the same upwardly through pipe 33, through plenum chamber '34 and openings 35, to force the circulation of quenching liquid upwardly and around the inside of the part 2 and thence down through tubes 11 and 8 as previously described, thus establishing a circulation of quenching liquid within tank 1 and within the interior of the part 2 being quenched to maintain a uniform quenching ternperature. At the same time, pump 27 will draw quenching liquid from storage jacket 4 down through pipe 38 and up through pipe 30, forcing this liquid out through apertures 32 in the annular quench manifold 31 and upwardly through tank 1 in surrounding relation to the body 2, thereby obtaining a uniform cooling of the exterior of body 2 at the same time as the interior of this body is uniformly cooled. Pump 28 will assist pump 27 in this operation.

Thus, it will be seen that the body 2. obtains rapid and uniform quenching both exteriorly and interiorly, so that the same is not distorted and retains its proper shape after the quenching operation. After the desired period of quench, the part 2 is withdrawn from the tank 1. As the part 2 is withdrawn from the tank, the counter-weight 17 is free to move the telescoping sleeve 11 and vent 36 upwardly until these parts again reach their initial position shown in Fig. 1. Continued operation of pump 26 will now draw the liquid out of Standpipe 24 and out of tubes 11 and 8, so that the liquid level in these tubes rapidly falls allowing air to enter the same until switch 25 opens and pumps 26 and 27 stop pumping. The remaining liquid in pipes 24 and 8 as well as that in conduits 23and 21 is withdrawn by the scavenger pump 28 and forces it up through pipes 29 and 30 into the tank 1 preparatory for another operation of the quench tank. when the liquid level in sump tank 19 reaches the desired height such as that shown in Fig. 1, the pump 28 stops and the quench tank is ready for another operation.

Since many changes could be made in the above construction of'the novel quenching apparatus of this inventron and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. Quenching apparatus comprising a tank adapted to contain quenching liquid, a telescoping tube extending upwardly within said tank and having an open upper end adapted to extend above the quenching liquid, conduit means for connecting said tube with the outside atmosphere so that, when a hollow body to be quenched is inserted into said tank from above, the air therewithin may escape through said telescoping tube and into the atmosphere, the upper open end of said tube being depressed by the body as it moves downwardly into said tank so that as said open end enters the quenching liquid the latter flows into said tube, pumping means, and piping connecting said pumping means to said tube and said tank, whereby said pumping means circulates quenching liquid from said tube back into said tank for maintaining substantially a uniform quenching liquid temperature throughout said tank during the quenching operation.

2. Quenching apparatus as defined in claim 1 wherein said conduit means comprises a standpipe exterior of said tank and having an open upper end for allowing air to escape into the atmosphere, and a liquid level switch communicating with said standpipe for efiecting the starting of said pumping means when quenching liquid flowing from said tank through said telescoping tube and into said standpipe reaches a predetermined height therewithin.

3. Quenching apparatus as defined in claim 1 wherein a quenching liquid storage jacket is provided around the exterior of said tank for receiving quenching liquid spilled from said tank during the immersion of the hollow body thereinto, and including additional pumping means, and connected piping connecting said additional pumping means from said storage jacket to said tank for effecting the pumping of quenching liquid from the former and into the latter for circulating therein.

4. Quenching apparatus comprising a quench tank adapted to be filled substantially to its open top with quenching liquid, a quenching liquid storage jacket surrounding said tank for receiving quenching liquid overflowing the top of said tank, pumping and conduit means connecting said storage jacket to said quench tank for pumping quenching liquid from the former into the latter to effect the circulation of quenching liquid within said quench tank, a sump tank positioned below said quench tank, a telescoping tube positioned within said quench tank and extending upwardly therein with its upper open end adapted to project above the liquid surface level therein, said telescoping tube extending below the bottom of said quench tank and into the upper portion of said sump tank, a standpipe positioned exteriorly of said quench tank, piping means connecting the upper portion of said sump tank with said standpipe, movement of a hollow body to be quenchd into the quench tank serving to drive the air within the body through said telescoping tube, said sump tank, said piping means and said standpipe to the atmosphere, the body upon engaging said telescoping tube serving to depress said tube below the liquid level in the quench tank so that liquid within the tank flows downwardly through said telescoping tube and into said sump tank, said connected piping means, and into said standpipe, and additional pumping and conduit means connecting said piping means to said quench tank for circulating quenching liquid flowing into said telescoping tube back into said quench tank to aid said initial pumping means to effect circulation of quenching liquid within said quench tank.

5. Quenching apparatus as defined in claim 4 wherein said telescoping tube is provided with a counterweight for raising the upper part of said tube above the liquid level in said quench tank when the quenched body is removed from said tank.

6. Quenching apparatus as defined in claim 4 wherein a plenum chamber surrounds said telescoping tube and has discharge openings disposed about said tube, said plenum chamber being interposed between said additional pumping and conduit means and said quench tank to effect the cooling of the interior of the body being quenched.

7. Quenching apparatus as defined in claim 4 wherein said quench tank is provided with a quench manifold extending therewithin near the side walls of said tank, said manifold being connected to said first-mentioned pumping and conduit means so that quenching liquid from said storage jacket is forced upwardly within said quench tank adjacent the side walls thereof to eifect the cooling of the exterior of the body being quenched.

8. Quenching apparatus as defined in claim 7 wherein a scavenger pump and connected conduit interconnects said sump tank with said quench manifold, whereby said scavenger pump aids said first-mentioned conduit and pumping means to efiect the circulation of quenching liquid around the exterior of the body being quenched.

9. In quenching apparatus of the character described, a quench tank open at its top and adapted to hold quenching liquid, a telescoping tube extending upwardly within said tank having a vent opening at its top normally positioned above the liquid level in said tank, conduit means connecting the lower portion of said tube to the atmosphere, said telescoping tube serving, upon the immersion of a hollow body into said tank, initially to allow air to escape from within the body to the atmosphere, and, when its vent opening is depressed below the liquid level in said tank by the downward pressure of the body upon said tube, said tube serves to remove quenching liquid from within the body, and pumping means connected to said tube and said tank to circulate said removed liquid back into said tank to maintain uniform temperature of the quenching liquid therein.

10. In quenching apparatus of the character described, a quench tank open at its top and adapted to hold quenching liquid, a telescoping tube extending upwardly within said tank having a vent opening at its top normally positioned above the liquid level in said tank, conduit means connecting the lower portion of said tube to the atmosphere, said telescoping tube serving, upon the immersion of a hollow body into said tank, initially to allow air to escape from within the body to the atmosphere, and, when its vent opening is depressed below the liquid level in said tank by the downward pressure of the body upon said tube, said tube serves to remove quenching liquid from within the body, and pumping means connected to said tube and said tank to recirculate said removed liquid back into said tank to maintain uniform temperature of the quenching liquid therein, said conduit means comprising an exterior standpipe and a liquid level switch thereon for controlling the operation of said pumping means.

11. Quenching apparatus as defined in claim 10 wherein a quenching liquid storage jacket surrounds said quench tank for catching liquid overflowing therefrom when the body to be quenched is introduced thereinto, and additional pumping means as connected to said jacket and to said quench tank for circulating quenching liquid from said jacket into said quench tank to aid in maintaining the temperature of the quenching liquid uniform throughout the tank.

12. Quenching apparatus as defined in claim 11 wherein a sump tankcommunicates with said telescoping tube and a scavenger pump is connected with said sump tank for draining quenching liquid out of said telescoping tube and for pumping the same back into said quench tank.

13. Quenching apparatus as defined in claim 12 wherein a quenching liquid filter is included in said first-named pumping means connected between said tube and said tank.

References Cited in the file of this patent UNITED STATES PATENTS 2,872,364 Sherwood Feb. 3, 1959 

